Twice a year, gamers from all over the world come together to "speedrun" both new and old games alike. Games from every platform and every era. Even better, it's a week-long marathon to raise money for charity, and it's streamed live on Twitch for millions to follow along. Although I'm not a big gamer, I've been watching both Awesome Games Done Quick(AGDQ) and Summer Games Done Quick(SGDQ) for about five years now.
Each marathon gets better. More games, larger sponsors, more money raised, and, finally, better production quality. The SGDQ that just finished raised over $3 Million for Doctors Without Borders, and the production and organization is top-notch. Specifically, I was impressed with the donation tracker.